Seat belt systems are used to restrain passengers in automobiles, aircraft, recreational utility vehicles (RUVs), and other vehicles in the event of a crash or other potentially dangerous event. In automobiles, seat belt systems typically include a belt or web that can be pulled from a web retractor fixedly attached to a mounting structure on one side of a vehicle seat. The web can be extended across the occupant's body, and the free end of the web, which typically carries a connector tongue, can be releasably engaged with a buckle anchored to the base of the seat or the floor opposite the web retractor. Conventional web retractors typically include a spring-loaded spool that maintains tension on the web and retracts the web when it is not in use.